摘要
为了研究钢管混凝土缺陷试件的徐变性能,进行了7组徐变试验研究,得到了钢管混凝土缺陷试件补强前后徐变度随持荷时间的变化曲线。研究结果表明:相较于无缺陷钢管混凝土,存在缺陷的钢管混凝土徐变度均有不同程度增大,其中,脱黏缺陷钢管混凝土试件的徐变度增量远大于空洞缺陷试件;脱黏缺陷削弱了钢管与混凝土之间的界面黏结,致使钢管与混凝土的应力重分布作用减弱,协同变形能力下降;空洞缺陷处混凝土由于发生应力集中而加剧了裂缝的产生和扩张,混凝土因此而发生错位滑移,增大了钢管混凝土的附加变形;注浆补强后,钢管混凝土的徐变变形减小,但相较于无缺陷钢管混凝土,缺陷补强钢管混凝土的徐变性能仍存在一定程度的折减。
In order to study the creep performance of concrete filled steel tube defect specimens, 7 groups of creep tests were carried out, and the curves of creep degree with load holding time before and after strengthening were obtained. The results show that compared with the non-defective concrete-filled steel tube, the creep degree of the defective concrete-filled steel tube increases to different degrees, among them, the creep increment of the specimens with debonding defects is much larger than that with cavity defects. The debonding defect weakens the interface bonding between steel tube and concrete, which weakens the stress redistribution effect of steel tube and concrete, and reduces the cooperative deformation capacity. The stress concentration of concrete at the cavity defect intensifies the generation and expansion of cracks, which leads to the dislocation slip of concrete and increases the additional deformation of concrete-filled steel tube. After grouting, the creep deformation of concrete-filled steel tube decreases. However, compared with concrete-filled steel tube without defects, the creep behavior of reinforced concrete filled steel tube is still reduced to some extent.
作者
郝兆峰
张戎令
王起才
祁强
庄立普
黄国栋
HAO Zhaofeng;ZHANG Rongling;WANG Qicai;QI Qiang;ZHUANG Lipu;HUANG Guodong(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;National and Local Joint Engineering Laboratory of Road and Bridge Engineering Disaster Prevention Technology,Lanzhou Jiaotong University,Lanzhou 730070,China;Department of Architectural Engineering,Pingliang Vocational and Technical College,Pingliang 744000,China;China Railway 21 Bureau Group Co.,Ltd.,Lanzhou 730070,China)
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2020年第5期1191-1199,共9页
Acta Materiae Compositae Sinica
基金
青年人才托举工程
飞天学者特聘计划
长江学者和创新团队发展计划滚动支持(IRT_15R29)
国家自然科学基金(51768033)
甘肃省高校协同创新科技团队支持计划(2017C-08)。
关键词
钢管混凝土
徐变
脱黏
空洞
缺陷
注浆补强
concrete filled steel tube
creep
debonding
cavity
defect
grouting reinforcement
